It is known in the art relating to hemming and stamping that conventional hemming and stamping presses include a lower structural member supported by the floor or foundation with columns mounted to the lower structural member and extending vertically upwards to support an upper fixed structural member. The upper fixed structural member supports an actuation apparatus which may include a hydraulic cylinder(s), electric crank type actuator or other drive type mechanisms. An upper slidable structural member or ram is slidably mounted between the lower structural member and upper fixed structural member on a guidance system which may include a single or multiplicity of guide shafts, gibs and wear plates, or rolling type guides. Furthermore, a removable die set that consists of a lower die and upper die are supported by the lower structural member and upper slidable structural member/ram. The lower die set is fixedly mounted to the lower structural member whereas the upper die is fixedly mounted to the upper slidable structural member/ram. This type of mounting method normally forces the press structure to be greater in size than needed for the die set, causing the press structure to cost more than required for a certain product.
Conventional hemming and stamping presses impose difficulties and obstructions during general maintenance and repairs on die sets. Die sets that are placed in a conventional press are usually surrounded on two sides by columns that are vertical members that mount to the lower structural member and support the upper fixed structural member of a press. Maintenance and/or repair performed in these obstructed areas of the die sets can be cumbersome and dangerous due to worker being inside the press during the repair. Another option for maintenance and repair in these obstructed areas is to remove the die set from the press structure. This in itself can add to the down time of a production run and impose an additional cost of operation. Removal of a die set from a press normally requires the use of additional equipment such as a frame work on which to roll and support the die set, or a die cart or lift truck capable of supporting the weight of the die set. Furthermore, conventional moderately sized to larger sized hemming/stamping equipment or presses require disassembly due to their inherent excessive physical size or weight during transportation and then reassembly at their final destination or area that at which they will be operated.
Conventional hemming and stamping presses are also known to be square or rectangular in shape as viewed from above in plan view, which necessitates greater spacing between the products being hemmed or stamped. This is due to the product workpiece normally being much smaller than the press that is performing the hemming/stamping operation as well as the shape of the structure. The columns of a hemming and stamping press normally are on the sides perpendicular to the load/unload side. With the columns of the hemming and stamping press perpendicular to the load/unload side, a second hemming press must be spaced away from the first hemming press by a centerline distance that is half the product width plus the distance between the edge of the product and the clearance to the inside of the column plus the column width and a clearance value between the two hemming presses. As shown in FIG. 7, a known process for a hemming system with four products is to have two hemming presses spaced apart and in line with each other. A second set of two hemming presses are spaced opposite the first two hemming presses to create four presses spaced apart with their load/unload sides facing opposite each other. A material handling robotic arm is positioned centrally between all four opposing hemming presses. The material handling robot is normally mounted to a slidable transfer unit to enable the material handling robot to reach all four products in the hemming presses. A marriage/load stand is spaced centrally between the two opposing leading hemming presses and an unload stand is spaced centrally between the two opposing trailing hemming presses.